Digital circuits driving bus systems or input/output cables often have requirements for driving relatively high capacitance lines. Some systems are designed to require fast fall-times only, in which open-collector circuits are used with passive pull-up. In other systems, fast rise times are also required. Typically, fast rise times are achieved by providing high-current active pull-up and pull-down driver circuits, sometimes called "totem-pole" driver circuits. In some systems, however, multiple devices may be able to pull a line low or some devices on the same line may be powered off. In addition, damage can occur if a line is accidently shorted to ground. Some current limitation is needed to prevent damage if a line is shorted, or if one device attempts to pull a line low while another device is pulling the line high or if some devices connected to a line are powered off. Existing solutions include adding series resistance to output drivers. When a line is pulled low through a series resistor, voltage drops across the series resistor can decrease noise margins. A solution is needed that provides high transient current to overcome line capacitance but limited steady state current to prevent damage due to shorts, or damage if devices have power off, or damage due to drive conflicts between devices.